Study finds an important reason to wear three-layer face masks

Over the past several weeks, questions and suggestions have been raised over the potential benefit that comes with wearing three face masks — or masks made with three layers of fabric instead of one or two. A new study out of California has found a good reason to upgrade your face masks to this design, noting that three layers of fabric are much more effective against risky large droplets.

Most face masks feature a single layer of fabric, but some masks are higher-quality and often feature two layers: an inner piece of fabric, often with a pocket for inserting a filter, as well as a thicker outer layer. The idea behind multiple layers is that they're better able to protect against small droplets and particles that would otherwise pass through the pores in a single fabric layer.

Three layers, the reasoning goes, are better able to protect against these small droplets compared to two. A new study out of the University of California – San Diego has found another good reason to upgrade your face masks: triple-layer masks also better protect against large droplets like the kind that result from sneezing and coughing.

These large droplets are particularly risky because they may contain much higher viral loads compared to smaller droplets. When the large droplets pass through fabric, they atomize into smaller droplets, which linger in the air longer and put the people around you at risk of infection.

Triple-layer masks, according to the new study, are much more effective at preventing these droplets from passing through the fabric and atomizing into the surrounding air. The findings were based on the use of a high-speed time-lapse camera and droplet generator. The researchers note that while three-layer face masks are ideal, wearing single- and double-layer face masks are still much better than not wearing a mask.